Thank God, I found this article! Few days back, when I was trying to modify one of my blog’s theme footer (I had to add sitemeter code next to the footer links), I saw such kind of codes. Initially I could not understand anything from that code and hence thought of removing that suspicious long code from the footer.php. But surprisingly my blog went down and it did not open. It was displaying a notice “Theme Error”.
I could not dare to take any chance. So, I restored the footer.php from the backup via FTP client. And then everything started working normally. After that I simply changed that theme and now using another one.
Also, I have seen few themes with malicious iframe links in the footer. So, it’s a wise idea to check theme files manually before using.